This invention relates to lubricating compositions and, more particularly, is directed to water-soluble lubricants useful in tabletting processes for producing water soluble effervescent tablets.
In the making of many effervescent cleansing and medicinal tablets, it is customary to provide the active ingredients in a relatively dry, granular form which are thoroughly blended prior to the tabletting process. The mixed granular ingredients are then fed from a gravity or forced feed hopper into a linear or rotary punch and die press where they are compacted under the influence of pressure into the desired tabletted form. Once the tablet is formed in the die it is released therefrom and suitably packaged for its intended use.
It has also been customary in such tabletting processes to include, along with the granular starting materials, a lubricant in order to permit the granulated starting materials to flow evenly and smoothly through the hoppers of the tablet press and into the die cavities thereof. The lubricants further enhance the compaction of the granulated starting materials into elegant tablets without any sticking or build-up of the granular material on the tablet punches or on the die walls.
Heretofore, the best lubricants for accomplishing such purposes have been insoluble substances such as magnesium stearate or talc. Many water-soluble substances have been tried as lubricants in tabletting processes, substances such as boric acid, sodium benzoate, polyethylene glycol 6000 micronized, boric acid powder, fumaric acid powder, polyvinylpyrrolidone, and the like, but none have been found to function as well in the tabletting process as the insoluble magnesium stearate to talc-like substances.
In the tabletting of active ingredients which desirably are rapidly dissolved in water, such waterinsoluble lubricants which function best in the tabletting process have a deleterious effect on the dissolution of the active ingredients in water. While not only tending to inhibit the rate of dissolution of the water soluble effervescent tablets in water, the insoluble lubricants as have been used heretofore in the tabletting process have also caused the resulting solutions to appear cloudy and unclear.
It would, therefore, be desirable to have a water-soluble lubricant substance or substances which function as well as or better than the water-insoluble lubricants used theretofore, in order to provide tabletted products, such as denture cleansers, antacids, angalgesics and the like, in which the tablet is rapidly dissolved in water to form a sparkling, clear effervescent solution.